A 3D radiative transfer framework - XI. Multi-level NLTE

  title={A 3D radiative transfer framework - XI. Multi-level NLTE},
  author={Peter Hauschildt and Edward A. Baron},
  journal={Astronomy and Astrophysics},
Multi-level non-local thermodynamic equilibrium (NLTE) radiation transfer calculations have become standard throughout the stellar atmospheres community and are applied to all types of stars as well as dynamical systems such as novae and supernovae. Even today spherically symmetric 1D calculations with full physics are computationally intensive. We show that full NLTE calculations can be done with fully 3 dimensional (3D) radiative transfer. With modern computational techniques and current… 

Atomic line radiative transfer with MCFOST

Aims. We present MCFOST-art, a new non-local thermodynamic equilibrium radiative transfer solver for multilevel atomic systems. The code is embedded in the 3D radiative transfer code MCFOST and is

Recent advances in non-LTE stellar atmosphere models

  • A. Sander
  • Physics
    Proceedings of the International Astronomical Union
  • 2016
Abstract In the last decades, stellar atmosphere models have become a key tool in understanding massive stars. Applied for spectroscopic analysis, these models provide quantitative information on

Coupling hydrodynamics with comoving frame radiative transfer. II. Stellar wind stratification in the high-mass X-ray binary Vela X-1

Context. Vela X-1, a prototypical high-mass X-ray binary (HMXB), hosts a neutron star (NS) in a close orbit around an early-B supergiant donor star. Accretion of the donor star’s wind onto the NS

Supernovae Type Ia & Dark Energy

In project C5 of the SFB 676, we simulated the spectra of cosmological Type Ia supernovae in detail. We use state-of-the-art (3D) NLTE spectral synthesis to analyze the observed multi-wavelength

A new EOS module for the atmosphere modelling code PHOENIX

PHOENIX is a general-purpose atmosphere modelling code. To enhance its capability to model terrestrial conditions, a new equation of state (EOS) module is required to determine the chemical

Supernova 1987A: neutrino-driven explosions in three dimensions and light curves

The well-studied type IIP SN 1987A, produced by the explosion of a blue supergiant (BSG) star, is a touchstone for massive-star evolution, simulations of neutrino-driven explosions, and modeling of

Solar Science with the Atacama Large Millimeter/Submillimeter Array—A New View of Our Sun

The Atacama Large Millimeter/submillimeter Array (ALMA) is a new powerful tool for observing the Sun at high spatial, temporal, and spectral resolution. These capabilities can address a broad range

Modeling the Hα Emission Surrounding Spica Using the Lyman Continuum from a Gravity-darkened Central Star

The large, faint Hα emission surrounding the early B-star binary Spica has been used to constrain the total hydrogen recombination rate of the nebula and indirectly probe the Lyman continuum


We present ultraviolet, optical, and near-infrared observations of SN 2012ap, a broad-lined Type Ic supernova in the galaxy NGC 1729 that produced a relativistic and rapidly decelerating outflow



A 3D radiative transfer framework. II. Line transfer problems

Context. Higher resolution telescopes as well as 3D numerical simulations will require the development of detailed 3D radiative transfer calculations. Building upon our previous work we extend our

A 3D radiative transfer framework - IX. Time dependence

Context. Time-dependent, 3D radiation transfer calculations are important for the modeling of a variety of objects, from supernovae and novae to simulations of stellar variability and activity.

A 3D radiative transfer framework: V. Homologous Flows

Context. Observations and theoretical calculations have shown the importance of non-spherically symmetric structures in supernovae. Thus, the interpretation of observed supernova spectra requires the

A 3D radiative transfer framework - VI. PHOENIX/3D example applications

Aims. We demonstrate the application of our 3D radiative transfer framework in the model atmosphere code PHOENIX for a number of spectrum synthesis calculations for very different conditions.

A 3D radiative transfer framework - X. Arbitrary velocity fields in the comoving frame

Aims. General 3D astrophysical atmospheres will have random velocity fields. We seek to combine the methods we have developed for solving the 1D problem with arbitrary flows to those that we have

3D radiative transfer effects in parametrized starspots

Aims. We use our 3D radiative transfer framework to investigate how the presence of a parametrized starspot a ff ects radiative transfer in stellar atmospheres in general, and molecular CO lines in a

A 3D radiative transfer framework. I. Non-local operator splitting and continuum scattering problems

We describe a highly flexible framework to solve 3D radiation transfer problems in scattering dominated environments based on a long characteristics piece-wise parabolic formal solution and an

A 3D radiative transfer framework: IV. spherical & cylindrical coordinate systems

We extend our framework for 3D radiative transfer calculations with a non-local operator splitting methods along (full) characteristics to spherical and cylindrical coordinate systems. These

A 3D radiative transfer framework VII. Arbitrary velocity fields in the Eulerian frame

Aims. A solution of the radiative-transfer problem in 3D with arbitrary velocity fields in the Eulerian frame is presented. The method is implemented in our 3D radiative transfer framework and used

A 3D radiative transfer framework: XIII. OpenCL implementation

The kernel for solving the 3DRT problem in Cartesian coordinates with periodic boundary conditions in the horizontal $(x,y)$ plane is implemented, including the construction of the nearest neighbor $\Lstar$ and the operator splitting step.